I am looking to find out the names of the best Eiswein makers in Germany. I'm looking on the behalf of my boss...I myself am clueless about this type of wine. Anyone know who these individuals may be? Your help is greatly appreciated.

Welcome to the board.
I have limited recent experiences with German Eiswein. (I used to be able to afford the .375 ml bottles on occasion when I lived in Germany more than a decade ago.) One I have liked recently is the Weingut Karlsmuhle Lorenzhofer (Ruwer River tributary so a Mosel-Saar-Ruwer wine). Highly praised are the Donnhoff Oberhauser Brucke Eisweins. Doubt you could go wrong with them (Nahe region of Germany). Other worthy producers are Dr. von Basserman-Jordan from the Pfalz and Reinhold Haart and Dr. Loosen from the Mosel region. These are just a few. Eiswein depends on certain weather conditions in the late fall and risking leaving grapes on the vines until a solid frost when rain or other things could ruin the crop. Also the grower needs to have pickers ready to pick the grapes while still frozen. Therefore, some vintages do not produce many Eisweins and not all vintners make an Eiswein every year. I believe Donnhoff is one that usually offers one or more Eisweins each year.

Thanks to both of you for your helpful tips. My boss is considering producing Eiswein at his estate in New England and would like to talk to a few experts as to whether this is a viable idea. You've given me a few jumping off points; thanks again for your help!

Don't know where your boss has his estate in New England, but I seriously doubt if he'll be able to make a true Eiswein here. First, the conditions aren't very favorable to grow the right grapes. Typically, Eiswein is made from Riesling and I don't know of anyplace here that would provide the two conditions necessary. First, the grapes have to hang on the vines until they get the right weather conditions to freeze the grapes without first rotting - New England weather is very humid and that promotes mold and rot. Second, the grapes must be very hardy to survive New England's harsh winters without having the next year's buds freeze and die. There are fourteen or so wineries in Massachusetts alone, and I know of none of them that has successfully produced an Eiswein. Just out of curiosity, where is this New England estate located?